Effect of Geogrid Reinforcement on Bearing Ratio of Two Layered Soil

The effect of utilization of geogrid on the improvement of the load-settlement characteristics of two layered soil and reduction of the needed subbase layer thickness in unpaved roads is studied. Bearing Ratio tests were conducted for two layered soil including a granular soil layer at the top and a cohesive soil placed at the bottom in unsoaked condition. These tests were performed for unreinforced and reinforced by geogrid placed at the interface of two layers and considering different thickness for top layer (granular soil). The experiment shows that the bearing ratio of two layered soil is enhanced when reinforced with geogrid. For all of the sand layer thicknesses (40, 55 and 70 mm) the relative bearing ratio factor remains almost the same with penetration increment and this value increases with reducing the sand layer thickness.

Keywords:

Geosynthetic , Subgrade , Subbase , Thickness of subbase , Bearing ratio test